Obesity among Mexican-American women has the potential to become a public health crisis. Hispanics are one of the fastest growing minority populations in the United States and the prevalence of obesity in Mexican American woman is increasing at an alarming rate. Poor dietary practices, especially food habits that are acquired as families acculturate to the American food supply, and lack of exercise are thought to be associated with women's excess weight gain. Accordingly, interventions are needed to improve the dietary intake and physical activity levels of Mexican-American families. We propose to conduct a randomized clinical trial in which women are randomly assigned to receive either family-based behavioral counseling (FBC) sessions and play group physical activity sessions or group based nutrition and exercise classes and health related activity worksheets to complete with their child. The FBC sessions, conducted by community health advisors, will use photographs of the family's food practices, taken by mothers, as visual aids in the counseling sessions. The control intervention will consist of group sessions using curricula designed to motivate women to exercise and to promote the Food Guide Pyramid recommendations using traditional Mexican-American foods. The primary outcome of the trial is mother's BMI. The secondary outcomes are dietary intake, moderate to vigorous physical activity and household food supplies. We hypothesize that within a one year timeframe, women who are exposed to the FBC will have lower BMI's compared to women who receive the active placebo control intervention. The mechanisms through which we intend to change weight status are altering the type of foods purchased and cooking practices and promoting mothers to engage in physical activities with their children during their play. Measurements of secondary outcomes include three 24 hour dietary recalls, a household food inventory and activity monitoring using MTI actigraph monitors. In addition, mothers'reports of household food security level, and food purchase motives, will be collected as covariates. Measurements will be collected within one month of completing the interventions and at six months and one year follow-up. Relevance to public health: Mexican-Americans are one of the fastest growing populations in the United States. They are also experiencing increasingly high levels of obesity. This research compares two nutrition and exercise programs designed to prevent obesity. One program is family-based and the other is traditional group based sessions.